High CO Yield Research Articles

A2V2O7 (A = Co, Ni, Cu and Zn) for CO2 reduction under visible-light irradiation: Effects of A site replacement

Electronic structure and surface character are two important factors of materials for photocatalytic CO2 reduction. Herein, the simultaneous regulation of electronic structure and surface basicity of pyrovanadate A2V2O7 (A = Co, Ni, Cu, Zn) were realized by changing the A-site element. The density functional theory (DFT) results suggested that Ni2V2O7 had the strongest crystal field and the greatest splitting of V 3d, resulting in the largest mobility of photogenerated electrons. Moreover, the Tanabe hypothesis predicted that the A-site cation was a basic surface site, and the CO2-TPD results revealed that Ni2+ had the strongest surface basicity. Ni2V2O7 exhibited much higher CO yield of 33.1 μmol/g, compared to Co2V2O7 (16.7 μmol/g) and Zn2V2O7 (12.9 μmol/g). Cu2V2O7 was not suitable for CO2 reduction due to its positive conduction band position caused by splitting the Cu 3d orbital. Altogether, this study could contribute to deeply understanding metal vanadates for photocatalytic CO2 reduction.

Graphitic carbon nitride/antimonene van der Waals heterostructure with enhanced photocatalytic CO2 reduction activity

Photocatalytic reduction of CO 2 into valuable fuels is one of the potential strategies to solve the carbon cycle and energy crisis. Graphitic carbon nitride (g-C 3 N 4 ), as a typical two-dimensional (2D) semiconductor with a bandgap of ∼2.7 eV, has attracted wide attention in photocatalytic CO 2 reduction. However, the performance of g-C 3 N 4 is greatly limited by the rapid recombination of photogenerated charge carriers and weak CO 2 activation capacity. Construction of van der Waals heterostructure with the maximum interface contact area can improve the transfer/seperation efficiency of interface charge carriers. Ultrathin metal antimony (Sb) nanosheet (antimonene) with high carrier mobility and 2D layered structure, is a good candidate material to construct 2D/2D Sb/g-C 3 N 4 van der Waals heterostructure. In this work, the density functional theory (DFT) calculations indicated that antimonene has higher carrier mobility than g-C 3 N 4 nanosheets. Obvious charge transfer and in-plane structure distortion will occur at the interface of Sb/g-C 3 N 4 , which endow stronger CO 2 activation ability on di-coordinated N active site. The ultrathin g-C 3 N 4 and antimonene nanosheets were prepared by ultrasonic exfoliation method, and Sb/g-C 3 N 4 van der Waals heterostructures were constructed by self-assembly process. The photoluminescence (PL) and time-resolved photoluminescence (TRPL) indicated that the Sb/g-C 3 N 4 van der Waals heterostructures have a better photogenerated charge separation efficiency than pure g-C 3 N 4 nanosheets. In-situ FTIR spectroscopy demonstrated a stronger ability of CO 2 activation to *COOH on Sb/g-C 3 N 4 van der Waals heterostructure. As a result, the Sb/g-C 3 N 4 van der Waals heterostructures showed a higher CO yield with 2.03 umol g −1 h −1 , which is 3.2 times that of pure g-C 3 N 4 . This work provides a reference for activating CO 2 and promoting CO 2 reduction by van der Waals heterostructure.

Separate H2 and CO production from CH4‐CO2 cycling of Fe‐Ni

AbstractCH4‐CO2 chemical looping is proposed for separate H2 and CO production using nanostructured Fe‐Ni looping materials. The product streams are obtained by first feeding CH4, which decomposes to H2 and carbon. The latter acts as reductant for the subsequent CO2 feed, which together with Fe re‐oxidation yields CO. After 25 CH4‐CO2 cycles, 10Fe5Ni@Zr has a higher H2 space–time yield than 10Fe0Ni@Zr ( vs. ), a 2.6 times higher CO yield () and lower deactivation. This improvement has two reasons: (i) CH4 activation over Ni leading to cracking, (ii) product hydrogen causing deeper FeO reduction. Deactivation follows from accumulated carbon, non‐reactive for CO2. On Ni and Fe sites, carbon can be removed by lattice oxygen or CO2, yielding more CO compared to the theoretical value for Fe oxidation. However, carbon that migrates away from the metals requires oxygen for removal, which restores the activity of the Ni‐containing samples.

Novel p- and n-type S-scheme heterojunction photocatalyst for boosted CO2 photoreduction activity

S-scheme photocatalysts are more efficient than the conventional type-II configuration, but the CO2 reduction performances are still unsatisfactory. Herein, we firstly report the layered double hydroxide (LDH) based S-scheme heterostructure photocatalyst (NiIn LDH/In2S3) with n-type NiIn LDH and p-type In2S3. The built-in internal electric field directs the photogenerated electrons flow from the conductive band of In2S3 to the valance band of NiIn LDH, which is confirmed by operando and theoretical experiments. The CO2 photoreduction intermediates are monitored by in-situ Raman spectra, and the density functional calculations disclose the reduced energy barrier for CO desorption on the heterojunction. Therefore, without cocatalysts or sacrificial agents, the NiIn LDH/In2S3 heterojunction delivers a high CO yield rate of 29.43 μmol g−1 h−1 under visible light irradiation, ca. 3.5 and 4.3 times higher than the single counterpart NiIn LDH and In2S3. Notably, this value is the highest among S-scheme CO2 photocatalysts and surpasses most top-ranking benchmarks.

Direct solar thermochemical CO2 splitting based on Ca- and Al- doped SmMnO3 perovskites: Ultrahigh CO yield within small temperature swing

Solar thermochemical CO2 splitting is a promising route to reduce environment pollution and mitigate energy crisis. However, traditional redox materials are limited by low CO production, slow reaction kinetics, and poor cycling stability, which results in low solar-to-fuel efficiency. Here, Ca- and Al- doped SmMnO3 perovskites are proposed for high-performance solar thermochemical CO2 splitting. The average CO yield of Sm0.6Ca0.4Mn0.8Al0.2O3 reaches a record-high value of 595.56 μmol g−1 when swinging between 1350 °C and 1100 °C. The CO yield is about 4.22 times as high as that of undoped SmMnO3 (140.97 μmol g−1) under the same conditions, and remains stable over multiple cycling. The ultrahigh CO yield can be attributed to the transformation of reaction mechanism from solid-state surface reaction (F2) to bulk diffusion model (D2). Besides, Ca- and Al- doped SmMnO3 perovskites possess high solar absorptance over 86.5% (in stark contrast to 12.1% of CeO2), so that only solar concentration ratio of 898 (Sm0.6Ca0.4Mn0.8Al0.2O3) is required to drive thermochemical reactions while benchmark CeO2 needs 1936. This work provides novel approaches for high-performance solar thermochemical CO2 splitting with high CO yield, good cycle stability, small temperature swing, and low solar concentration required.

Insight into biomass pyrolysis mechanism based on cellulose, hemicellulose, and lignin: Evolution of volatiles and kinetics, elucidation of reaction pathways, and characterization of gas, biochar and bio‐oil

Pyrolysis is the first step of gasification and combustion. The pyrolysis process of biomass is complicated, which is generally considered to consist of the pyrolysis of the three major components (i.e., cellulose, hemicellulose, and lignin). Understanding the pyrolysis behavior and product of each component holds a key to understanding the biomass pyrolysis mechanism. In this work, the pyrolysis behavior, pyrolysis kinetics, volatile evolution, and product characterization of the three major components are investigated. Results showed that pyrolysis characteristics and thermal stability of the three components were closely related to their unique chemical structures. During pyrolysis, the main pyrolytic volatiles of hemicellulose appeared first, followed by cellulose and then lignin volatiles in the 3D FTIR spectra. In term of pyrolysis products, gases were generated by the cracking of specific functional groups. Hemicellulose had the highest CO2 yield, whereas lignin had the highest CH4 yield due to the aromatic rings and methoxy groups in lignin structure. Whereas cellulose demonstrated the highest CO yield at high temperatures (above 550 °C). With increasing temperature, the carbon structures of carboxylic-C and O-alkyl-C in biochar decreased, while aryl-C was enhanced. This was due to the deoxygenation reactions such as dehydroxylation, decarboxylation, decarbonylation, and demethoxylation, resulting in a reduction in the number of oxygen-containing functional groups (such as –OH, –C=O, –COOH, and –OCH3), as well as the polycondensation reactions that formed more polycyclic aromatic hydrocarbon units during pyrolysis. The major components of cellulose bio-oil included anhydrosugars and furans. Whereas the bio-oils derived from hemicellulose and lignin showed the highest relative content of acids and phenols, respectively. Based on this analysis, the thermal decomposition pathways of cellulose, hemicellulose, and lignin were proposed.

Optimization of Algae Residues Gasification: Experimental and Theoretical Approaches

Abstract Gasification is one of the thermochemical pathways of biomass conversion that produces synthesis gas, tar, and char. This study aims to convert algal residues via gasification at different operating conditions; temperature, equivalence ratio, and biomass loading. The study was carried out in 3 steps; (1) testing the outcomes of temperature and loading effects on synthesis gas yield, (2) experimental optimization of gasification via Design Expert, and (3) theoretical optimization of gasification via Aspen Plus simulation. Temperature and equivalence ratio highly influenced synthesis gas composition, while loading demonstrated less effect on the synthesis gas composition. The experimental and simulated gasification outcomes were compared to obtain optimized conditions that produce high H2 and CO yields. The data were validated using root mean square error. The optimized temperature, loading, and equivalence ratio were found for both algal residues that produced 36.38 and 13.28mol% of H2 and CO, respectively for lipid extracted algae (LEA) and 47.99 and 26.05mol% of H2 and CO, respectively for fucoidan extracted seaweeds (FEA). There was a considerable variation between experimental and simulated data due to the simulation and experimental limitations. The average Carbon Conversion Efficiency values were 66.36 and 80.42% for LEA and FES, respectively, denoting that LEA produced less carbon-containing products, while FES produced more carbon-containing products. In conclusion, LEA gasification yielded more H2 while FEA produced more CO.

Low temperature CO2 conversion facilitated by the preserved morphology of metal oxide-perovskite composite

This work addresses the effect of incorporating a small portion of LaFeO3 into Fe2O3 on CO2 splitting in reverse water-gas shift chemical looping. Bare Fe2O3 suffers deactivation due to the structural change from sintering and agglomeration as the reaction progresses. The applied LaFeO3 perovskite acts as a sintering barrier between metal oxides, blocking the transport of metallic cations between adjacent particles and alleviating the Kirkendall effect by changing the direction of oxide growth. As a result, the structural deformation can be prevented, allowing sustainable CO2 conversion. In addition, the electrical conductivity of the particles is increased with the addition of the perovskite, and the conduction of the oxygen anions is improved accordingly. Therefore, Fe2O3-LaFeO3 demonstrates both enhanced CO yield and stability at the same time. It presents the highest CO yield (12.1 mmol/gcat) and CO production rate (605 μmol/gcat/min) for 50 redox cycles reported to date at 750 K.

Confining and Highly Dispersing Single Polyoxometalate Clusters in Covalent Organic Frameworks by Covalent Linkages for CO2 Photoreduction.

Single clusters have attracted extensive research interest in the field of catalysis. However, achieving a highly uniform dispersion of a single-cluster catalyst is challenging. In this work, for the first time, we present a versatile strategy for uniformly dispersed polyoxometalates (POMs) in covalent organic frameworks (COFs) through confining POM cluster into the regular nanopores of COF by a covalent linkage. These COF-POM composites combine the properties of light absorption, electron transfer, and suitable catalytic active sites; as a result, they exhibit outstanding catalytic activity in artificial photosynthesis: that is, CO2 photoreduction with H2O as the electron donor. Among them, TCOF-MnMo6 achieved the highest CO yield (37.25 μmol g-1 h-1 with ca. 100% selectivity) in a gas-solid reaction system. Furthermore, a mechanism study based on density functional theory (DFT) calculations demonstrated that the photoinduced electron transfer (PET) process occurs from the COF to the POM, and then CO2 reduction and H2O oxidation occur on the POM and COF, respectively. This work developed a method for a uniform dispersion of POM single clusters into a COF, which also shows the potential of using COF-POM functional materials in the field of photocatalysis.

Enhanced visible-NIR absorption and oxygen vacancy generation of Pt/HxMoWOy by H-spillover to facilitate photothermal catalytic CO2 hydrogenation

Pt/HxMoWOy with strong plasmonic absorption and abundant oxygen-defects achieves high CO yield in photothermal catalytic CO2 hydrogenation at low temperature.

3D Fe-MOF embedded into 2D thin layer carbon nitride to construct 3D/2D S-scheme heterojunction for enhanced photoreduction of CO2

Regulating charge transfer to achieve specific transfer path can improve electron utilization and complete efficient photoreduction of CO2. Here, we fabricated a S-scheme heterojunction of CN/Fe-MOF by an in-situ assembly strategy. The S-scheme charge transfer mechanism was confirmed by band structure, electron spin resonance (ESR) and work function (Φ) analysis. On the one hand, the response of Fe-MOF in the visible region improved the utilization of light energy, thus increasing the ability of CN/Fe-MOF to generate charge carriers. On the other hand, CN, as the active site, not only had strong adsorption capacity for CO2, but also retained photogenerated electrons with high reduction capacity because of S-scheme charge transfer mechanism. Hence, in the absence of any sacrificial agent and cocatalyst, the optimized 50CN/Fe-MOF obtained the highest CO yield (19.17 μmol g−1) under UV-Vis irradiation, which was almost 10 times higher than that of CN. In situ Fourier transform infrared spectra not only revealed that the photoreduction of CO2 occurred at the CN, but also demonstrated that the S-scheme charge transfer mechanism enabled 50CN/Fe-MOF to have a stronger ability to generate HCOO− than CN.

Hexanuclear nickel-based [P4Mo11O50] with photocatalytic reduction of CO2 activity

A new polyoxometalate based organic-inorganic hybrid [Ni6(trz)2(Htrz)13][H4P4Mo11O50]·7H2O (1), constructed from a hexanuclear [Ni6(trz)2(Htrz)13] building block and a new polyoxometalate [H4P4Mo11O50] cluster, was synthesized under a hydrothermal condition. In this 3D structure, each [Ni6(trz)2(Htrz)13] secondary building unit (SBU) connects with four neighbored [Ni6(trz)2(Htrz)13] and four [H4P4Mo11O50] clusters, forming an eight-connected node. While each [H4P4Mo11O50] cluster bridges four [Ni6(trz)2(Htrz)13] SBUs as a four-connected node. So the 3D framework of 1 can be simplified to a binodal (4, 8)–connected gsp2 topology with point symbol [44·62][416·612]. The photocatalytic reduction of CO2 under visible light reveals that the highest yield of CO was 689.86 μmol g−1 when 1 is used as catalyst, Ru(bpy)3Cl2 as a photosensitizer and TEOA as a sacrificial agent. The mechanism of the photoreduction of CO2 is confirmed by Mott-Schottky, photocurrent, and fluorescence quenching experiments. This research provides a new strategy for the design of cheap and efficient POM-based photocatalysts.

Product characteristics and potential energy recovery for microwave assisted pyrolysis of waste printed circuit boards in a continuously operated auger pyrolyser

The efficient disposal and recycling of nonmetal materials from waste printed circuit boards (WPCBs) can be a significant challenge due to their toxicity and complexity. In this paper, the characteristics and energy recovery of products from WPCBs pyrolysis at different temperatures were investigated using a two-mode auger pyrolyzer operated continuously under microwave irradiation. The results indicated that the organic matter in WPCBs was almost completely recovered (88.03%) and the maximum condensate yield (22.66 wt%) was obtained at 550 °C, with lower brominated compounds (1.83%) and higher phenols recovery (80.4%). Pyrolysis oil with low moisture content (0.5–2%) could be directly separated in-situ from condensates. Pyrolysis residue (PR) was further separated into valuable glass fiber and powder char with a certain degree graphitization by ball-milling. Bromine and sulfur mostly remained in powder char. The highest yields of CO (11.61 wt%) and H2 (1.50 wt%) were obtained at 750 °C. Energy balance analysis showed that 90.25% of energy was recovered at 550 °C, providing an energy efficiency as high as 72.00%. Bromine mainly remained in PR in the form of inorganic bromine (44.35–56.00 wt%), and was transferred to gas phases (HBr and CH3Br) with temperature increasing.

Defect-engineering of Zr(IV)-based metal-organic frameworks for regulating CO2 photoreduction

Defects in MOFs can benefit light absorption and charge transfer for photocatalytic application, nevertheless, studies on interplay between structural defects and photocatalytic properties of MOFs are in infancy. Herein, a series of UiO-66-NH2 with different kinds of defects were created for regulating CO2 photocatalytic reduction. Theoretical calculations in combination with experimental data verified that the sample with ligand-vacant (UiO-66-NH2-LV) defect performed better than non-defect, missing-cluster and monocarboxylate compensated ones in the photocatalytic CO2 reduction reactions. UiO-66-NH2-LV shows superior photocatalytic activity with the highest CO yield of 30.5 μmol g−1h−1, which is 9.2 times higher than that of the sample with missing-cluster (UiO-66-NH2-MC), as well as the highest quantum yield (QY) of 0.90%. DFT calculations further demonstrate the correlation between discriminative photocatalytic activities in defect structures and tunable electronic properties characterized by absorption energy, Eabs, and charge transfer energy, ELMCT, in the photocatalytic process. The ligand-vacant defect with the lowest sum of Eabs and ELMCT will lower photocatalytic reaction energy barrier in the rate-limiting step among the elementary reaction step during CO2 photoreduction. The insights gained from this study will guide the MOFs defect-engineering for enhancing CO2 photocatalytic capacity.

Boosted charge transfer and photocatalytic CO2 reduction over sulfur-doped C3N4 porous nanosheets with embedded SnS2-SnO2 nanojunctions

Two-dimensional porous nanosheet heterostructure materials, which combine the advantages of both architecture and components, are expected to feature a significant photocatalytic performance toward CO2 conversion into useful fuels. Herein, we provide a facile strategy for fabricating sulfur-doped C3N4 porous nanosheets with embedded SnO2-SnS2 nanojunctions (S-C3N4/SnO2-SnS2) via liquid impregnation-pyrolysis and subsequent sulfidation treatment using a layered supramolecular structure as the precursor of C3N4. A hexagonal layered supramolecular structure was first prepared as the precursor of C3N4. Then Sn4+ ions were intercalated into the supramolecular interlayers through the liquid impregnation method. The subsequent annealing treatment in air simultaneously realized the fabrication and efficient exfoliation of layered C3N4 porous nanosheets. Moreover, SnO2 nanoparticles were formed and embedded in situ in the porous C3N4 nanosheets. In the following sulfidation process under a nitrogen atmosphere, sulfur powder can react with SnO2 nanoparticles to form SnO2-SnS2 nanojunctions. As expected, the exfoliation of sulfur-doped C3N4 porous nanosheets and ternary heterostructure construction could be simultaneously achieved in this work. Sulfur-doped C3N4 porous nanosheets with embedded SnO2-SnS2 nanojunctions featured abundant active sites, enhanced visible light absorption, and efficient interfacial charge transfer. As expected, the optimized S-C3N4/SnO2-SnS2 achieved a much higher gas-phase photocatalytic CO2 reduction performance with high yields of CO (21.68 μmolg−1 h−1) and CH4 (22.09 μmolg−1 h−1) compared with the control C3N4, C3N4/SnO2, and S-C3N4/SnS2 photocatalysts. The selectivity of CH4 reached 80.30%. Such a promising synthetic strategy can be expected to inspire the design of other robust C3N4-based porous nanosheet heterostructures for a broad range of applications.

Comparisons of visible-light driven photocatalytic CO2 conversion performances over mesoporous CdSxSe1–x with different molecular compositions

This study presents a synthesis method for nanowire arrayed mesoporous CdSxSe1-x compounds with different S/Se molar ratios. Both ternary and binary compound semiconductors are synthesized by hard-templating using SBA-15 as a silica template. The synthesized mesoporous materials have high specific surface areas of approximately 65–100 m2 g−1 and remarkable light absorption properties in the UV to visible light region (1.7–2.4 eV), and thus they are appropriate for the photo-conversion of CO2 into CO and CH4. The results show that the compositions of CdSxSe1-x excellently agree with the compositions of the reactants. Moreover, the band gaps of the mesoporous CdSxSe1-x samples could be directly tuned by varying the composition of the reactants. It is concluded that mesoporous CdSe achieves the highest CH4 yield rate, i.e., 0.382 μmol gcat–1 h–1, and CdS0.5Se0.5 achieves the highest CO yield rate (among all the samples synthesized), i.e., 5.633 μmol gcat–1 h–1. Also, it is found that the CO2 photoconversion performance on mesoporous II-VI photocatalyst are highly affected by CO2 adsorption capacities and photo-generated charge separation.

Efficient Photocatalytic Reduction of CO2 to CO Using NiFe2O4@N/C/SnO2 Derived from FeNi Metal-Organic Framework.

Use of light is considered an effective approach to convert CO2 into usable chemical energy. In the present study, an iron- and nickel-containing bimetallic metal-organic framework (MOF) was synthesized via a simple solvothermal route. SnO2 was then composited with the said MOF, and the obtained material was calcined and annealed to fabricate a series of nanophotocatalysts. The annealed sample displayed superior photocatalytic activity to the calcined sample, possibly due to the carbon-nitrogen layer formed after annealing mediating the charge-transfer process. The results of photocatalytic experiments indicated that using [Ru(bpy)3]Cl2·6H2O as a photosensitizer and triethanolamine (TEOA) and acetonitrile (MeCN) as sacrificial agents, the catalyst sample was annealed at 450 °C (NiFe2O4@N/C/SnO2-450) to afford the highest CO yield from CO2 (2057.41 μmol g-1 h-1). The increase in the photocatalytic ability of the nanocomposites is basically attributed to multiple synergistic effects between NiFe2O4 and SnO2, which reduce the recombination probability of the photo-induced electrons and holes. Ultimately, a photocatalytic reaction mechanism is proposed for NiFe2O4@N/C/SnO2 in the reduction of CO2.

Achieving simultaneous Cu particles anchoring in meso-porous TiO2 nanofabrication for enhancing photo-catalytic CO2 reduction through rapid charge separation

A facile solvo-thermal approach was successfully employed to prepare titanium oxide (TiO2) nano-aggregates with simultaneous copper particles anchoring. The as-synthesized composite could convert CO2 into CH4 and CO products under simulated solar irradiation. The impact of copper loading amounts on the photo-reduction capability was evaluated. It was found proper amount of Cu loading could enhance the activity of CO2 photo-reduction. As a result, the optimal composite (TiO2-Cu-5%) consisting of TiO2 supported with 5% (mole ratio) Cu exhibits 2.2 times higher CH4 yield and 3 times higher CO yield compared with pure TiO2. Conduction band calculated from the band gap and valence X-ray photoelectron spectroscopy (XPS) indicated TiO2 nano-aggregates have suitable band edge alignment with respect to the CO2/CH4 and CO2/CO redox potential. Furthermore, with involving of Cu particles, an efficient separation of photo-generated charges was achieved on the basis of photocurrent response and photoluminescence spectra results, which contributed to the improved photo-catalytic performance. The present work suggested that the Cu-decorated TiO2 could serve as an efficient photo-catalyst for solar-driven CO2 photo-reduction.

Tungsten oxide quantum dots deposited onto ultrathin CdIn2S4 nanosheets for efficient S-scheme photocatalytic CO2 reduction via cascade charge transfer

A novel S-scheme photocatalytic heterojunction composite nanomaterial is developed by integrating zero-dimensional WO3 quantum dots (WQDs) on two-dimensional ultrathin CdIn2S4 (CIS) nanosheets with the aim of fostering carrier separation, enhancing the performance of carrier interface transport, minimizing carrier distance transport, and achieving effective photocatalytic CO2 reduction. The composite photocatalyst WQDs/CdIn2S4 (WCIS) allows for the efficient photocatalytic reduction of CO2 to CO and CH4, as shown by product analysis and isotopic measurement. The photogenerated electrons in WQDs recombine with the holes in CIS nanosheets, and the left electrons in CIS have stronger CO2 reduction abilities. The highest yields of CO and CH4 achieved with the WCIS photocatalyst are 8.2 and 1.6 μmol g-1h−1 ––2.6 and 8 times higher than those for CIS, respectively. Moreover, the S-scheme WCIS possesses a stable crystal structure and recycling ability. Finally, the S-scheme charge transfer path on the WCIS composite is proposed according to theoretical calculation, in-situ irradiated X-ray photoelectron spectroscopy, and electron paramagnetic resonance (ESR) analyses.

Molten-salt-mediated carbon dioxide capture and superequilibrium utilization with ethane oxidative dehydrogenation

Existing CO2-mediated oxidative dehydrogenation (CO2-ODH) of ethane has yet to demonstrate >60% single-pass CO yield due to the intrinsic equilibrium limitations. We report a unique approach with mixed molten carbonates as a reaction medium for CO2-ODH, which strategically partitions the CO2-ODH reactions into gas and molten-salt phases and facilitates integrated CO2 capture from power plant flue gases. An 89% CO yield was achieved at 770°C, doubling the equilibrium limitation of conventional CO2-ODH. The high CO yield in turn enhances ethylene formation. Further characterizations confirmed that molten-salt mediated ODH (MM-ODH) proceeds through a gas-phase cracking and molten-salt mediated reverse water-gas-shift reaction pathway. Based on this understanding, thermodynamic analysis and ab initio molecular dynamics simulations were conducted to develop general principles to optimize the molten-salt reaction medium. Process analyses confirm that MM-ODH has the potential to be significantly more efficient for CO2 capture and utilization than conventional CO2-ODH.